import i18n from '@/lang'
// @copy vue-element-plus-admin
type I18nGlobalTranslation = {
  (key: string): string
  (key: string, locale: string): string
  (key: string, locale: string, list: unknown[]): string
  (key: string, locale: string, named: Record<string, unknown>): string
  (key: string, list: unknown[]): string
  (key: string, named: Record<string, unknown>): string
}

type I18nTranslationRestParameters = [string, any]

const getKey = (namespace: string | undefined, key: string) => {
  if (!namespace) {
    return key
  }
  if (key.startsWith(namespace)) {
    return key
  }
  return `${namespace}.${key}`
}

/**
 * @description 多语言
 * @author jinzz
 * @param namespace 语言文件类
 * @desc: 包含有global下面所有方法
 * @example
 * import { useI18n } from '@hooks/useI18n'
 * const { t } = useI18n("menu")
 * t('数据看版')
 * 
 * or
 * 
 * import { useI18n } from '@hooks/useI18n'
 * const { t } = useI18n()
 * t('menu.数据看版')
 */
export const useI18n = (
  namespace?: string
): {
  t: I18nGlobalTranslation
} => {
  const normalFn = {
    t: (key: string) => {
      return getKey(namespace, key)
    }
  }

  if (!i18n) {
    return normalFn
  }

  const { t, ...methods } = i18n.global

  const tFn: I18nGlobalTranslation = (key: string, ...arg: any[]) => {
    if (!key) return ''
    if (!key.includes('.') && !namespace) return key
    return (t as any)(getKey(namespace, key), ...(arg as I18nTranslationRestParameters))
  }
  return {
    ...methods,
    t: tFn
  }
}
